JPS5914019A - Controller of heater - Google Patents

Abstract

PURPOSE:To prolong the life of a heater, by arranging a temperature switch to be opened at the upper limit temperature or more and a high power setter, and a temperature switch to be closed at the upper limit temperature or more and a low power setter in parallel, respectively. CONSTITUTION:An object to be heated is heated at high electric power W1 when the peripheral temperature is maximum B, but excess heat more than necessary causes the upper limit TH of a controlling range to be exceeded. However, a temperature switch 23a is opened and a temperature switch 23b is closed immediately after exceeding the upper limit TH, so that low electric power W2 is supplied to the heater and the object to be heated is heated by a low output. Since sufficient heat to be required at the maximum of peripheral temperature is supplied, the temperature of the object to be heated is reduced because heat supplied from the initial status is finally reduced, and balanced status is kept in the control range.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides: (1) A temperature control device such as an electric heatless device that keeps piping and equipment warm within the temperature range of a special vehicle. = Heater control device C that controls the supplied power.

In general (= electric temperature control device), it detects the temperature of the object to be heated which is to be maintained at a constant temperature (= The temperature of the heated object is controlled by applying a corresponding amount of heat to the heated object using a heater that generates heat.

The heater control device described above is composed of a temperature switch that detects the temperature of the heated object, opens the circuit at a high set temperature, and closes the circuit at a low set temperature. It is incorporated inside. That is, a heated object is heated by a heater, and when the temperature of the heated object exceeds a high set temperature, a temperature switch is opened to open the heater circuit, and power supply to the heater is cut off. Then, when the temperature drops to the low set temperature, the temperature switch closes to close the heater circuit, and power is supplied to the heater again to heat the object to be heated.

On the other hand, the heater is used only when the ambient temperature is at its lowest (such as during winter).
42 also needs to have sufficient heat capacity to maintain the temperature of the heated object, and the unit output of the heater is divided into stages for convenience of manufacture. Therefore, it is difficult to select a heater that matches the required output, so a heater with a relatively large capacity is selected.

However, in the case of a large-capacity heater like the one mentioned above, when the ambient temperature is at its highest (such as in the summer), the heat capacity becomes considerably larger than the required heat capacity, so in the heater control device like the one mentioned above, the m-degree switch frequently opens and closes. will be done. Accordingly, the power supply to the heater is intermittent, which shortens the heat cycle (the time interval during which the heater generates heat).
Intermittent high power consumption causes wear and tear on the heater core wire, shortening the lifespan of the heater. Also.

Heated object I: Excessive heat! 7￥ Intermittent 1 = feeding, which may cause damage due to thermal fatigue, which is not desirable.

This invention improves the above-mentioned drawbacks and makes it possible to set the heater output to an appropriate value (2), thereby preventing wear and tear on the heater core wire and prolonging the life of the heater. The present invention provides a heater control device that can prevent such problems.

That is, the heater control device according to the present invention has an upper limit temperature switch, a high power setting device, and a temperature switch that closes above the upper limit temperature and a low power setting device arranged in parallel and connected to a power controller. be.

An embodiment of the present invention will be described below with reference to one drawing and two drawings.

As shown in FIG.
It is an AC power supply that supplies power at the maximum output of
Electric power is supplied to the heater J41'' via the heater control device 15. This heater control device 15 detects the temperature of the heated object 11, and adjusts the temperature within the set range (2
'' - This is to control the electric power.The heater 14 has a capacity that is greater than or equal to the required capacity (C2) when the ambient temperature of the heated object 1) is the lowest.
Approximately 1.5 to 2 times) is used, and one heated object (
Install the two in close proximity. In other words, the heater control device 15 receives electric power (from the power supply circuit 13) corresponding to the required amount of heat.
Heat 1 is supplied to the heater 14 under two control, and
It gives

FIG. 2 shows the configuration of the heater control device 15.
Input terminal 16&I connected to power supply circuit 13 (not shown)
, 16b are connected to output terminals 18a and 18bl, which are connected to a heater 14 (not shown) via a power switch 17, thereby forming a heater circuit 19'4f. Then, the triac 20 is connected in series to one line 1 of the heater circuit 19, for example, to the circuit of the output terminal 18a. This triac 2
0 controls the energization time by switching the alternating current flowing through the heater circuit 19 every half cycle according to the phase pulse signal input from the gate G. Give a pulse signal.

This control circuit 21 transmits a pulse signal having the same period as the alternating current T generated in the power supply circuit 13, shifts the phase t of this pulse signal in proportion to the input voltage change, and transmits this phase pulse signal @ to the triac 20. This is what is supplied to the gate G of the circuit. In other words, this control circuit 2 and triac 2
0 constitutes a power controller 22, which controls the current flowing through the heater circuit 19 according to the input voltage value to set the power. The input voltage circuit for phase control for this power controller 22 includes a temperature switch 23a and a high power setting device 34g.
and a second circuit B consisting of a temperature switch 23b and a low power setting device 24b.
- thus a high or low power setting device 24 consisting of a series resistor;
The voltage signal set by m and 24b is supplied to the control circuit 21.

Here, the power setters 34a and 24b are each independent variable resistors, and by setting their resistance values, the voltage applied to the control circuit 211 is set. Set the resistance value at the designed minimum temperature (winter, etc.) within the temperature control range (to supply the power necessary to maintain the temperature).Also.

Low power setting device J? 4b sets the double resistance value at the designed maximum ambient temperature (summer, etc.) in the same way as the high power setting device j4b. Then, the temperature switches 23ta, 23
Temperature switch 23a is a switch that is directly attached to the heated body seam, and temperature switch 23a is a switch that opens when the upper limit of the warm control range is exceeded (2), and then closes again when the temperature falls below the lower limit of the control range. The switch closes when the control range exceeds the upper limit and then opens when the control range falls below the upper limit.

In other words, the temperature of the heated object 11 (=correspondingly, if one of the temperature switches 23a and 23b is closed, and if the temperature switch 23m is closed, the voltage set by the high power setting device 24a is set by the power controller The power controller 22 sets the phase of the pulse signal by the voltage value (-) supplied by the control circuit 2, and sends the phase-set gate pulse signal to the triac 20. Then, the heater circuit 19v is switched in accordance with the gate pulse signal supplied by the triac 20, and the alternating current tM flowing through the heater circuit]9 is controlled every half cycle (two energization phase is controlled), and the heater JJV generates heat with high power.

When the temperature switch 23b is closed, the voltage set by the low power setting device 24b is input to the power controller 22, and the energization phase of the triac 20 is delayed to control the amount of current flowing through the heater circuit 191. The heater 14v generates heat with low power and heats the object to be heated 11 with low power.

FIG. 3 shows the temperature change of the heated object when the heat tress 12 using the heater control device 15 is operated, when the ambient temperature is the lowest A.

When the power switch 17 of the heater control device 15 is closed, the temperature switch 23a is closed and the temperature switch 23b is open, so high power W) is supplied to the heater 14 (= object to be heated 11'4/heated). The temperature of the object to be heated 1) is in an equilibrium state within the control range since sufficient heat is given to maintain a constant temperature. In addition, when the ambient temperature is the maximum B, the heated object 11 is heated with high power W1 in the same way as when the ambient temperature is the maximum A, but an excessive amount of heat C2 is applied more than necessary (2, the upper limit of the control range). r1+H is exceeded. However, immediately after the upper limit +11H is exceeded, the C two-temperature change switch 23 opens and the temperature switch 23b closes, so low power W2 is supplied to the heater 14 and the heated object 11 is heated at low output. After that, the temperature of the heated object 11 is given the necessary and sufficient amount of heat for the maximum ambient temperature, so the amount of heat supplied decreases from the initial state, so the temperature decreases and reaches an equilibrium within the control range. The state becomes 1 again.
When the ambient temperature is between the lowest and highest ambient temperature C1 (-, the temperature of the heated object 11 is the upper limit of the control range because it is first heated with high power W1, but it still gives an excessive amount of heat) TH is reached.At this point, the temperature switch 23 is opened, the temperature switch 23b is closed, and low power W2 is supplied to the heater, so the amount of heat supplied decreases and the temperature drops.However, this amount of heat supplied is set when the ambient temperature is at its highest. Therefore, the temperature maintenance i2 is insufficient and the lower limit value TL of the control range is exceeded.However, immediately after the lower limit value TL is exceeded, the temperature switch 23a closes and the temperature switch 23h opens, so the high power W1 is The heater 14I is supplied with an excessive amount of heat to the heated object.The above operation is then repeated to maintain the temperature of the heated object within the control range.

Therefore, when the ambient temperature is the lowest or highest, high power W1 or W2 necessary and sufficient to maintain the temperature of the heated object 11 is supplied to the heater 14, so that the heater 14 is heated continuously; Since power is always supplied to the heater 14 by switching between the high power W1 and the low power W2 even when it is in the middle of the maximum power, the life of the heater 14 is dramatically extended compared to the conventional method of repeatedly disconnecting and disconnecting the source. 1=extends. Furthermore, since the heater 14 continuously heats the object 11 to be heated, damage caused by thermal fatigue can be prevented.

As described above (2) According to this invention I, power is controlled by arranging in parallel a temperature switch and a high power setter that open the heater control device at a temperature higher than the upper limit temperature, and a temperature switch and a low power setter that close the heater control device at a temperature higher than the upper limit temperature. 1) Connecting the heater to the heater continuously extends the life of the heater as power is continuously supplied to the heater. It can be prevented.

Furthermore, an appropriate heater output can be obtained using a commercially available inexpensive power controller and temperature switch, making it possible to provide an appropriate amount of heat to the heated object.

The heater itself can also be used in a long-term stable state.

In addition to the heat tress systems for equipment and piping mentioned in the embodiments, the present invention can also be used for equipment, anti-freezing equipment for piping, systems for heating liquids such as tanks, etc.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the configuration of an electric heat stress such as equipment and piping, and FIG. 2 is a diagram illustrating the configuration of a heater control device according to an embodiment of the present invention. FIG. 3 shows the temperature curve of the object to be heated when the heat tress using the heater control device described above is operated. 11...-Heated object, 12... Heat tress, 13...
... Power supply circuit, 14... Heater, 15... Heater control device, 16... Input terminal, 12°" power switch. 18... Output terminal, 19... Heater circuit, 20...
- Triac, 21... Control circuit, 22... Power controller, 23a... Temperature switch that opens above the upper limit temperature and closes below the lower limit value, 23b... Closes above the upper limit temperature and below the lower limit value. Open warm□□□ switch, 21ta・
...High power setting device, 24b...Low power setting device, A...
・Temperature curve of the heated object at the lowest ambient temperature, B...Temperature curve at the highest ambient temperature, C...Temperature curve when the ambient temperature is between the highest and lowest, W)...High Electric power, W2
...low power.

Claims (1)

[Claims] A heater control device in which a temperature switch and a high power setting device that open when the temperature exceeds the upper limit temperature, and a temperature switch and a low power setting device that closes when the temperature exceeds the upper limit are arranged in parallel and connected to a power controller.